Income taxes - Additional Information (Details) $ in Thousands				1 Months Ended	3 Months Ended	12 Months Ended
	Nov. 20, 2017 USD ($)	Nov. 14, 2017 notice	Oct. 05, 2017 notice	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Income Taxes [Line Items]
Loss carryforwards						$ 70,400
Loss carryforwards not subject to expiration						212,400
Tax Act, provisional amount related to transition tax					$ 80,580
Tax Act, transition tax payable, non-current							$ 46,295
Increase (decrease) in reserve for uncertain tax positions						(1,639)	(3,076)	$ 4,895
Tax Act, benefits included in valuation allowance							16,100
Tax credits						13,310	10,083	1,197
Tax credit offsetting GILTI tax						10,484
Global intangible low-taxed income (GILTI)						(12,340)	(12,878)	0
Net GILTI tax						1,856
Undistributed earnings						916,457
Unrecognized tax benefits						11,400	13,500
Accrued for interest						2,000	2,100
Interest benefit						600
Interest benefit						900
Interest expense						1,500
Settlements						700
Reserve for uncertain tax benefits						900
Number of NOPAs received | notice		2	2
2018 Tax year
Income Taxes [Line Items]
Estimate of net GILTI tax due						2,097
U.S. Federal
Income Taxes [Line Items]
Loss carryforwards						77,200
U.S. Federal | Plastic Packaging Inc.
Income Taxes [Line Items]
Loss carryforwards						15,800
Foreign
Income Taxes [Line Items]
Loss carryforwards						238,600
Foreign | Next five years
Income Taxes [Line Items]
Operating loss carryforwards subject to expiration						9,200
Foreign | 2025 to 2039
Income Taxes [Line Items]
Operating loss carryforwards subject to expiration						17,000
State
Income Taxes [Line Items]
Loss carryforwards						12,300
State credit carry forwards						17,600
Uncertain Items Arising During Year
Income Taxes [Line Items]
Increase (decrease) in reserve for uncertain tax positions						1,800	1,700	2,600
Uncertain Items Arising During Prior Years
Income Taxes [Line Items]
Increase (decrease) in reserve for uncertain tax positions						$ (3,500)	$ (2,900)	$ (2,300)
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Income tax examination, estimate of possible loss, penalties				$ 18,000
Income tax examination, estimate of possible loss	$ 89,000